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Biomedical subjects

J P Jaramillo-Correa

Publications and source records attributed to J P Jaramillo-Correa.

3 recordsLinked to original sources

Cross-species amplification of mitochondrial DNA sequence-tagged-site markers in conifers: the nature of polymorphism and variation within and among species in Picea.

Primers previously developed to amplify specific non-coding regions of the mitochondrial genome in Angiosperms, and new primers for additional non-coding mtDNA regions, were tested for their ability to direct DNA amplification in 12 conifer taxa and to detect sequence-tagged-site (STS) polymorphisms within and among eight species in Picea. Out of 12 primer pairs, nine were successful at amplifying mtDNA in most of the taxa surveyed. In conifers, indels and substitutions were observed for several loci, allowing them to distinguish between families, genera and, in some cases, between species within genera. In Picea, interspecific polymorphism was detected for four loci, while intraspecific variation was observed for three of the mtDNA regions studied. One of these (SSU rRNA V1 region) exhibited indel polymorphisms, and the two others ( nad1 intron b/c and nad5 intron1) revealed restriction differences after digestion with Sau3AI (PCR-RFLP). A fourth locus, the nad4L- orf25 intergenic region, showed a multibanding pattern for most of the spruce species, suggesting a possible gene duplication. Maternal inheritance, expected for mtDNA in conifers, was observed for all polymorphic markers except the intergenic region nad4L- orf25. Pooling of the variation observed with the remaining three markers resulted in two to six different mtDNA haplotypes within the different species of Picea. Evidence for intra-genomic recombination was observed in at least two taxa. Thus, these mitotypes are likely to be more informative than single-locus haplotypes. They should be particularly useful for the study of biogeography and the dynamics of hybrid zones.

Base Sequence↗

Contrasting evolutionary forces driving population structure at expressed sequence tag polymorphisms, allozymes and quantitative traits in white spruce.

Patterns of variation in quantitative characters and genetic markers were compared among six regional populations of white spruce [Picea glauca (Moench) Voss]. Although some phenotypic characters were correlated with latitude (r = 0.791), longitude (r = -0.796) and precipitation during the growing season (r = 0.789), variability at genetic markers was not correlated with geographical or bioclimatic variables, and followed neutral expectations. Estimates of genetic diversity and population differentiation for 14 allozymes (translated regions of coding genes) were essentially indistinguishable from those observed for 11 expressed sequence tag polymorphisms (ESTPs) from untranslated regions of coding genes. Variation among populations for quantitative traits such as eighth year height (Q(ST) = 0.082), thirteenth year height (Q(ST) = 0.069), total wood density (Q(ST) = 0.102) and date of budset (Q(ST) = 0.246), was greater than for allozymes (G(ST) = 0.014) and ESTPs (G(ST) = 0.019). These trends suggest a strong adaptive response in quantitative traits, contrasting to allozymes and ESTPs where no selective response could be detected and where populations appeared to be essentially in a migration-drift equilibrium.

DNA, Plant↗

Population genetic analysis of the genes APOE, APOB(3'VNTR) and ACE in some black and Amerindian communities from Colombia.

A population genetic study was carried out with the APOE, APOB and ACE loci in 17 Colombian human populations. Ten of them were Amerindian communities coming from the northeastern part of Colombia, Pacific region, Eastern Plains and Amazonia. Six were black populations from Providence Island, Caribbean and Pacific coasts. Finally, the Mestizo population of Bogota was studied as well. The APOE and ACE loci were in Hardy-Weinberg equilibrium, whereas the APOB locus was not studied in all populations. The genetic heterogeneity was substantially greater among the Amerindian populations (G(ST) = 0.059) than in the Afrocolombian populations (G(ST) = 0.009). Also the gene flow population pair estimates were so much higher among the Afrocolombian populations (Nm = 49.08 +/- 43.07) than among Amerindian populations (Nm = 9.66 +/- 18.04). Different phylogenetic and multivariant analyses showed that the Amerindian populations analyzed were clustered in three different arrays: one constituted by the Colombian northeastern and Pacific populations, the second one by the two Amazon populations (Coreguaje and Nukak) and the last one by the Yuco (the unique Caribbe-speaking population among those studied). The latter population was highly divergent from a genetic point of view from the remainder Amerindian populations studied. By using the Mantel test, the existence of a positive and significant correlation between the genetic and geographical distances found among Amerindian populations was demonstrated. This fact was not observed among the Afrocolombian populations. Nevertheless, an isolation-by-distance Slatkin analysis test did not show a significant clear structure of this special pattern among the Indian tribes studied.

Alleles↗